I've been brewing for a little over a year now and have been using mostly food grade, 5 gallon buckets i found at lowes. I've been keeping them clean and using star san to sterilize them when i'm getting ready to use them. recently, i was looking at getting a 6 gallon bucket for fermenting from morebeer.com to have a little more head space and reduce blow off. in the description, it said "We recommend using a bucket no more than five times for fermentation purposes do to the vulnerability." Is this true? I know I've probably used each of mine at least that many times, probably more. What point should you replace plastic bucket fermenters?